This specification relates to data communications.
Service providers utilize distributed networks to provide services to customers over large geographic areas. For example, communications companies utilize a distributed communications network to provide communications services to customers. Similarly, power companies utilize a network of power lines and meters to provide power to customers throughout a geographic region and receive data back about the power usage.
These service providers are dependent on proper operation of their respective networks to deliver services to the customers and receive data back regarding the services provided. For example, the service provider may want access to daily usage reports to efficiently bill their customers for the resources that are consumed or otherwise utilized by the customers. Therefore, it is important for data specifying resource utilization and other information to be reliably transmitted and/or received at specified intervals.
In power line communication networks, nodes in the network (e.g., meters, load control switches, remote service switches, and other endpoints) can provide updated information (e.g., power consumption information and/or node operating status information) by transmitting data over power lines. To increase the amount of data that can be provided over the power lines, the transmitters used by the meters utilize modulation techniques to encode multiple bits of data into the transmissions. For example, a node can use Quadrature Phase Shift Keying modulation to provide two bits of data. Similarly, a node can use 16 Quadrature Amplitude Modulation to provide four bits of data.
Different nodes communicating over a power line communication network (and many other networks), may have various data transmission requirements. For example, a first node may be required to provide twice as much data as another node. Additionally, the channels over which the nodes communicate can have various different channel characteristics. In the example above, the first node may communicate over a channel having a noise floor that is significantly lower than the other node.
Due to the various data rates that can be required of the nodes, as well as the substantial differences in channel characteristics, it can be difficult to select a modulation technique that provides for efficient transmission of data for each node. Further, the channel characteristics can vary significantly over time such that modulation techniques that are selected for the nodes at one point in time may not provide adequate performance at another point in time. In view of the challenges, modulation technique selection that considers the conditions in which the node is operating can facilitate more efficient data transmission.